Mowers for weeds growing on flat grounds or slope faces are disclosed in Japanese Laid-open Patent Application Nos. H7-87824, H8-256560, and H9-74849, for example.
The “mower for the slope face” disclosed in Japanese Laid-open Patent Application No. H7-87824 has its object to “provide a mower having a novel structure for slope faces, capable of efficiently and safely carrying out mowing operation on the slope face which has to be done regularly every year from a viewpoint of safety control of river and maintenance of fine view”, and to attain this object, “a fitting trestle also useful as a working stand is attached to the side of a bed of a moving vehicle equipped with a suspending device of a telescopic arm type and a connecting frame is coupled with the end of the slope face side of the fitting trestle by a pivot part of the connecting frame. On the other hand, rotary mowing blocks in number corresponding to the width of the slope face are connected in series to a coupling shaft end of a hydraulic motor integrated with the connecting frame and tires are attached to the outermost side of the blocks to forma rotary mowing main body. The rotary mowing main body is made into a suspended state by the suspending device of a telescopic arm type and lag of the tire fixed side of the block in low speed traveling of the moving vehicle is controlled to provide a mower for the slope face”. Further, the “mower” disclosed in Japanese Laid-open Patent Application No. H8-256560 has its object to “enable a mower to improve a mowing work efficiency and store a surface slope mowing apparatus in a suitable state in unused time by making an effective mowing breadth of the surface slope mowing apparatus to be readily and quickly adjustable according to a length or a state of a slope linking to a side edge of a running road face”, and to attain this object, “in a mower having a surface slope mowing apparatus mowing grasses on a slope linking to a side edge of a running road face at the side of the running machine body, the surface slope mowing apparatus is constructed to a reciprocation-type performing a nip-cutting by a relative lateral reciprocate sliding of mutual a pair of upper and lower blades and supported in freely controllable of angles to a longitudinal direction, in freely controllable of a position to a mowing width direction, and in freely swung to a longitudinal direction, then the surface slope mowing apparatus controlled by pulling up upward of the machine body is shaken backward to be able to store in a rear part side of the machine body in a fallen state”. Furthermore, the “mower machine for a slope” disclosed in Japanese Laid-open Patent Application No. H9-74849 has its object to “provide a mower machine for a slope safely and surely performable of a mowing work on a steep slant surface such as a bank with a simple operation without requiring expertness in spite of not requiring much labor”, and to attain this object, “this mower machine has an unmanned mower having a mowing device in front of a self-running machine body, controlling advancing, backing and an action of the mowing device by a remote operation and performing a mowing work in its advancing and a control truck having a remote operating device controlling advancing, backing of the unmanned mower and the action of the mowing device and a shed part of the unmanned mower. An electric winch device paying out a pulling wire connected to a rear part of the unmanned mower in advancing of the unmanned mower at a speed slower than its advancing speed and winding in backing of the unmanned mower at a speed higher than its backing speed, is provided in the shed part of the control truck”.
However, since the “mower for the slope face” disclosed in Japanese Laid-open Patent Application No. H7-87824 requires a moving vehicle equipped with a suspending device of a telescopic arm type, the size of the machine is prone to be relatively increased. In the “mower” disclosed in Japanese Laid-open Patent Application No. H8-256560, regardless of the cover body that is extendable in accordance with adjustment of a position to a mowing width direction of surface slope mowing apparatus, if the cross-section of the slope face is curved, a part of weeds remain uncut since the pair of upper and lower blades are not flexible. In the “mower machine for a slope” disclosed in Japanese Laid-open Patent Application No. H9-74849, the control truck installed on the top of slope may fall off on the slope face.
Hence, the present invention has its object to provide a self-propelled mower that has a relatively simplified structure, allows adjustment of the mowing width, can be used on curved slope faces, enables pruning high place works, and is resistant to falling down.